Urethral stromal tumor with pacemaker cell phenotype.

Penile malignancies are rare in developed countries. The authors present a case of a penile urethral mesenchymal tumor occurring in a 51-year-old Caucasian male and displaying light microscopic, immunohistochemical, and ultrastructural features suggestive of a pacemaker cell type, combined with a lack of diagnostic features of any other established tumor category. The immunohistochemical profile was intensely positive for vimentin, PKC theta, and NSE and weakly positive to nonreactive for CD34 and smooth muscle actin, and entirely negative for CD117 (c-kit), S-100, and other markers. C-kit and PDGFRA gene analysis showed no mutations. Electron microscopy revealed tumor cells with plentiful cytoplasm and cytoplasmic processes/filopodia, both filled with intermediate filaments and occasional solitary focal densities. There were also prominent smooth endoplasmic reticulum cisternae, caveolae, neurosecretory granules, particularly concentrated in cytoplasmic processes, and synaptic-type structures. Poorly formed basal lamina, gap junctions, and intercellular collagen aggregates, consistent with skeinoid-type fibers, were also noted. Interstitial cells with potential pacemaker function have been recently described in the lower urinary tract, including the urethra, and this tumor may be related to this cellular phenotype.

Venacavoscopy during nephrectomy for renal cell carcinoma with inferior vena caval thrombus.

PURPOSE: Renal cell carcinoma with inferior vena caval thrombus remains a complex challenge for the urologist. Aggressive surgery to remove all tumor can result in long-term survival. Liver transplant techniques, assistance from cardiac surgeons and bypass techniques can yield optimal vascular control but there is still a blind element inside the inferior vena cava when the thrombus is evacuated. We present data on a technique using a flexible cystoscope to evaluate the lumen of the intrahepatic and suprahepatic inferior vena cava after nephrectomy and tumor thrombectomy. MATERIALS AND METHODS: Seven patients underwent radical nephrectomy and tumor thrombectomy for renal cell carcinoma with inferior vena caval thrombus. During surgery and after removal of the tumor thrombus a flexible cystoscope was inserted into the venacavotomy for direct inspection of the inferior vena caval lumen. Any residual tumor was manipulated out of the lumen and removed. Patient records were reviewed for data on the time of this procedure, estimated blood loss, residual tumor, postoperative complications and survival. RESULTS: Venacavoscopy required an average additional 5.6 minutes and residual tumor was found in 3 of 7 patients. Average estimated blood loss was 1,170 cc and it was not affected by venacavoscopy. One patient experienced acalculous cholecystitis, possibly as a result of this procedure. Mean followup was 17.6 months with 5 of 7 patients alive. CONCLUSIONS: Venacavoscopy is a safe, reliable method of intraoperative inspection of the inferior vena cava that uses equipment and techniques familiar to every urologist. This can help prevent incomplete thrombectomy and disastrous pulmonary embolus.

Complete urinary tract extirpation: the University of Maryland experience.

OBJECTIVES: Complete urinary tract extirpation (CUTE) involves simultaneous bilateral nephroureterectomy, cystectomy or cystoprostatectomy, and the creation of a urinary diversion, if needed. Case reports of this operation have been published, but to our knowledge, this is the largest case series yet reported. We sought to evaluate the characteristics and outcomes of patients who underwent CUTE. METHODS: From 1994 to 2005, 9 patients underwent CUTE at our institution. We performed a retrospective chart review of these patients. The data reviewed included demographics, operative time, length of stay, complications, recurrences, and overall survival. RESULTS: Nine patients who underwent CUTE were identified. The mean patient age at the operation was 61 years. Five patients were men. The mean operative time was 356 minutes. Two patients required a blood transfusion. The length of stay averaged 10.8 days (range 6 to 47). Four patients had functioning renal allografts before and after surgery. Three patients needing dialysis received renal allografts postoperatively. The overall survival rate at a mean follow-up of 31 months was 86%. CONCLUSIONS: Although this report presented a small number of patients, it has illustrated that CUTE can be performed safely and allow definitive surgical treatment of patients with complex genitourinary pathologic findings.

Effect of botulinum toxin on detrusor overactivity induced by intravesical adenosine triphosphate and capsaicin in a rat model.

OBJECTIVES: To assess the effects of intravesical injection of botulinum toxin type A (BTX) on a model of detrusor overactivity induced by intravesical infusions of adenosine triphosphate (ATP) and capsaicin. BTX has recently been used clinically to treat overactive bladder syndromes without a precise knowledge of the mechanism of action. METHODS: Twelve Sprague-Dawley rats underwent BTX injections. Six received 1.0 U and 6 received 0.5 U. BTX injections were done at bladder tube placement. Ten rats received saline injections as controls. After 48 hours of recovery, all 22 animals underwent awake, conscious cystometrography (CMG), performed using both saline and ATP (20 mM) intravesical infusion at 0.074 mL/min. In another 4 rats, capsaicin (100 microM) was infused intravesically before and after the BTX injections. The CMG parameters calculated included bladder contraction pressures and contraction frequencies (contractions per minute or Herz). RESULTS: Intravesical saline CMG produced a contraction frequency of 0.78 +/- 0.10 Hz. Intravesical ATP doubled this voiding frequency to 1.45 +/- 0.18 Hz (P = 0.003). BTX treatment at 1.0 U reduced the frequency to 0.91 +/- 0.13 Hz (P = 0.02). BTX injection significantly decreased the bladder contraction pressure during saline and ATP CMG. However, 0.5 U BTX did not decrease ATP-induced overactivity; therefore, in the capsaicin experiments, 1.0 U BTX was used. Although BTX tended to reverse detrusor overactivity secondary to intravesical capsaicin, this difference was not statistically significant. CONCLUSIONS: Intravesical infusion of either ATP or capsaicin can induce detrusor overactivity. BTX was more effective in blocking the effect of ATP than of capsaicin, although BTX injection did show a trend in reducing the contraction frequencies and amplitudes induced by capsaicin. The clinical utility of using BTX to treat overactive bladder syndromes and bladder hypersensory states, especially those that may be caused by an augmentation of the purinergic pathway, should be studied further.

Laparoscopic kidney donation from patients older than 60 years.

BACKGROUND: The current study seeks to determine if the efficacy and safety of laparoscopic donor nephrectomy holds true when performed in patients older than 60 years of age. STUDY DESIGN: Medical records of 42 renal donors older than 60 years were reviewed compared with younger controls carefully matched for gender, race, nephrectomy side, auxiliary recipient procedures, and date of surgery. RESULTS: Preoperative baseline serum creatinine was identical in both groups (0.9 +/- 0.2 mg/dL) although controls had a slightly higher (NS) creatinine clearance (106.9 +/- 19.1 versus 100.0 +/- 35.5 mL/m). Operatively, there was no substantial difference between groups in operative time, warm ischemia time, estimated blood loss, number or size of ports used, and length of incision needed for removal of kidney. Intraoperative and postoperative complication rates were also equivalent between old and young donors. Postnephrectomy serum creatinine was identical. There was no increased length of hospitalization for older donors and they tended to require less morphine sulfate patient-controlled anesthesia. Recipient renal function was slightly better in the younger kidneys early and the difference became statistically significant at 6 to 12 months, but the magnitude of the improvement is not clinically important. CONCLUSIONS: Laparoscopic donor nephrectomy may be performed safely in patients older than 60 years of age. There was no increase in complication rates or length of hospital stay. Older donors did not have a greater increase in serum creatinine after donation compared with donors younger than 40 years of age, nor did recipients of these older kidneys have clinically significantly higher serum creatinine than recipients of kidneys from donors less than 40 years old.

Salvage of sildenafil failures referred from primary care physicians.

PURPOSE: Sildenafil citrate is an effective first line agent for most causes of erectile dysfunction. Primary care providers (PCPs) write the majority of these prescriptions and most failures of sildenafil therapy are subsequently referred to urologists for alternative therapies. Often it is concluded that the drug is ineffective when in actuality the failure is do to inadequate patient education. We examined patients referred from PCPs who were nonresponders to sildenafil therapy and attempted to convert them to responders through reeducation. MATERIALS AND METHODS: In a 2-year period 253 sildenafil nonresponders were evaluated by the same urologist (GNS). Patient reeducation consisted of viewing a brief videotape, personal instruction and detailed instruction sheets for the patient and his partner. Outcome measures were obtained through patient self-reporting of the Sexual Health Inventory for Men and a global assessment question. Responders were identified as those who answered positively latter or had a statistical improvement in the score of the former. RESULTS: Of the 253 patients reeducated 17 were excluded due to contraindications. Of the remaining nonresponders 41.5% achieved salvage with reeducation. Incorrect administration accounted for 81% of the failures. Average time with the physician was 12 minutes and 94% of the patients continued to respond at 26 months. CONCLUSIONS: Approximately 40% of patients with sildenafil failures referred from PCPs can be converted to responders through reeducation. Incorrect drug administration was the most common reason for correctable failure. Reeducation can be done in an efficient manner. New package materials may improve sildenafil outcomes and compliance.

Magnetic resonance spectroscopic imaging-guided brachytherapy for localized prostate cancer.

PURPOSE: Prostate brachytherapy (PB) entails the placement of radioactive sources throughout the entire prostate gland to treat localized cancer. Typically, the target volume in PB encompasses the entire prostate gland because of the inability to localize the cancer and the multifocal nature of this malignancy. However, because of the unique biochemical nature of the prostate gland, recent advances in magnetic resonance spectroscopic imaging (MRSI) of the prostate have allowed precise delineation of the cancer location within the prostate gland. This report reveals our initial experience of MRSI-guided PB. METHODS: A MRSI study was obtained in 15 localized prostate cancer patients before their scheduled PB. The results of this study were used to internally map 7 x 7 x 9-mm volumes of prostate tissue to assign cancerous areas a higher dose of radiation. Such tumor-bearing areas had a low citrate/(choline+creatine) ratio consistent with cancer. On the basis of the anatomic MRI and MRSI correlation, three-dimensional coordinates were assigned to the locations of MRSI-defined cancer. The entire target volume was treated to a standard prescription dose using I-125 or Pd-103. Abnormal citrate regions, termed the biologic tumor volume, were prescribed a dose of 130% of the target volume dose to dose escalate in the abnormal citrate regions while respecting the normal radiation tolerances of the surrounding areas. Three-dimensional treatment planning was used to perform the implant. RESULTS: Of the 15 prostate cancer patients evaluated, all had successful three-dimensional MRSI acquisition before their scheduled PB procedure. In 14 of the 15 patients planned with MRSI, the data were successfully incorporated into their treatment planning and were used to increase the radiation dose prescription to 130% in the MRSI-defined volumes. In 1 patient, MRSI revealed significant background artifact that made a focal boost impractical. Postimplant dosimetry confirmed a median V100 of 95% (range 72%-100%) in the 15 evaluated patients for the prescription dose. Furthermore, the median BTV100 for the abnormal citrate region was 90% (range 80-100%) as determined by postimplant dosimetry. Urethral and rectal dose-volume histograms were within normal limits. Morbidity was comparable with that for conventionally treated patients. CONCLUSION: MRSI offers a promising new approach for the delivery of ionizing radiation in PB. Although this series was small and with a short follow-up, MRSI-guided implants are feasible and warrant further investigation as a means of improving the therapeutic ratio in PB [corrected].